IMHO - from my experiences working tech support - take the time to read the fine manual (RTFM) that they went to the trouble to write. With your KA 6 Pro, if your manual is like mine, that only needs to be pages 7-14 and should take you less than 5 minutes.
I will agree that KA's instruction to unplug the mixer before you do anything is excessive ... but it is a safety thing so that if you stick your fingers in the paddle and turn it on - it's not their fault.
There are really only two places for it to make noise. One is the motor - turn it on without the bowl or any attachment and see if it makes the noise. It it doesn't - attach the bowl and the flat beater and turn it on to speed 1 - and watch and listen as the beater goes around the bowl. If it makes the noise all the time then you probably need to refer to page 10 - "Bowl To Beater Clearance" for instruction on how to adjust it. If it only makes the noise when the beater is at the back side of the bowl ... you need to refer to "To Attach Bowl" step #4 on page 7.
Unless your KA has a real problem - I'm betting the bowl wasn't seated properly.
"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain